<form action="/test/JsonToString" method="post" style="margin: 20px; max-width: 600px;">
    <div style="margin-bottom: 10px; font-size: 16px;">内容：</div>
    <textarea name="content" id="content" placeholder="请输入要加密的内容"
              style="width: 80%; height: 150px; padding: 8px; border: 1px solid #ddd; border-radius: 4px; font-size: 14px;"></textarea>
    <div style="margin-top: 15px;">
        <input type="submit" value="提交"
               style="padding: 8px 16px; background-color: #4CAF50; color: white; border: none; border-radius: 4px; cursor: pointer; font-size: 14px;">
    </div>
</form>
